Zoom digital cameras comprising a Wide sub-camera and a folded fixed Tele sub-camera. The folded Tele sub-camera may be auto-focused by moving either its lens or a reflecting element inserted in an optical path between its lens and a respective image sensor. The folded Tele sub-camera is configured to have a low profile to enable its integration within a portable electronic device.

An optical imaging system includes a first lens group, a second lens group, and a third lens group, sequentially arranged from an object side, wherein the first lens group includes two lenses having negative and positive refractive power, the second lens group includes a plurality of lenses, and the third lens group includes two lenses having negative and positive refractive power.

The anamorphic objective zoom lens includes, along an optical axis and in order from an object space to an image space: at least a negative (−) power spherical first lens group; an anamorphic second lens group, spherical third lens group preferably having positive (+) power, a variable power spherical fourth lens group and a positive (+) power spherical fifth lens group. The aperture stop is located before, after or preferably within the spherical fifth lens group. All spherical lens groups contain spherical and piano refractive optical surfaces. The anamorphic second lens group contains cylindrical and plano optical surfaces with at least one cylindrical surface oriented at substantially 90 degrees about at least one other cylindrical surface. The spherical first lens group may provide focusing. The variable power spherical fourth lens group provides zooming. The spherical third and fifth lens groups may provide compensation for thermal defocus.

An optical system includes a first lens unit that has positive refractive power, a second lens unit that moves during focusing and that has positive refractive power or negative refractive power, and a third lens unit that has positive refractive power or negative refractive power. The first lens unit, the second lens unit, and the third lens unit are disposed in that order from an object side to an image side. During focusing, an interval between adjacent lens units changes. In the optical system, a focal length f of the entire optical system, a distance LD along an optical axis from a lens surface of the first lens unit that is closest to the object side to an image plane, and focal lengths of positive and negative lenses that are included in the first lens unit are appropriately set.

A zoom lens system according to the present disclosure includes a plurality of lens groups each of which is made up of at least one lens element. The zoom lens system includes, in order from an object side to an image side: a first focusing lens group having a negative power; and a second focusing lens group having a positive power, wherein when zooming is performed from a wide end to a telephoto end, the first focusing lens group and the second focusing lens group move along an optical axis, when focusing is performed from an infinity focusing state to a proximity object focusing state, the first focusing lens group and the second focusing lens group move to perform the focusing, and a predetermined condition is satisfied.

A lens unit with a central axis is provided. The lens unit includes a fixed portion, a movable portion, and a first driving assembly. The fixed portion includes an outer frame and a bottom combined with the outer frame. The outer frame and the bottom are arranged along the central axis. The movable portion is movably connected to the fixed portion, and carries a lens with an optical axis. The central axis is not parallel to the optical axis. The first driving assembly is connected to the movable portion, and drives the movable portion to move relative to the fixed portion. The first driving assembly also includes a biasing element made of a shape memory alloy.

A zoom optical system includes a first lens group, a position of which with respect to an imaging plane is adjustable, and including first and second lenses. The zoom optical system also includes a second lens group of which a position with respect to the imaging plane is adjustable and includes third to fifth lenses. The zoom optical system further includes a third lens group including a sixth lens. An object-side surface of the first lens is convex.

Zoom digital cameras comprising a Wide sub-camera and a folded fixed Tele sub-camera. The folded Tele sub-camera may be auto-focused by moving either its lens or a reflecting element inserted in an optical path between its lens and a respective image sensor. The folded Tele sub-camera is configured to have a low profile to enable its integration within a portable electronic device.

A zoom lens is provided. The zoom lens includes a first lens group, a second lens group, a third lens group and an aperture stop. The second lens group is disposed between the first lens group and the third lens group. The aperture stop is disposed between the first lens group and the second lens group. When the zoom lens zooms, the aperture stop is fixed without moving and the first lens group correspondingly moves.

A zoom lens has a four-group zoom configuration, in order from the object side to the image side, consisting of negative, positive, positive, and positive refractive power. The zoom lens carries out zooming from the wide-angle end to the telephoto end mainly by changing the distance between the third lens group and the fourth lens group. Also, the distance between the second lens group and the third lens group may be decreased in the zooming. Focusing is carried out mainly by moving the second lens group along the optical axis. Such a zoom lens is thin and small in size, and has a great imaging performance.